Free Testosterone ELISA Assay Kit


The Free Testosterone ELISA Assay Kit is intended for the direct quantitative determination of free testosterone in human serum. The Free Testosterone ELISA Assay Kit is for research use only and not to be used in diagnostic procedures.

SKU: TSF31-K01 Categories: , ,

Free Testosterone ELISA Assay Kit

The Free Testosterone ELISA Assay Kit is For Research Use Only

Size: 1×96 wells
Sensitivity: 0.018 pg/mL
Dynamic Range: 0.1–60 pg/mL
Incubation Time: 75 minutes
Sample Type: Serum
Sample Size: 25 µL
Controls Included

Assay Principle

The principle of the Free Testosterone ELISA Assay Kit enzyme immunoassay test follows the typical competitive binding scenario. Competition occurs between an unlabelled antigen (present in standards, controls and patient samples) and an enzyme-labelled antigen (conjugate) for a limited number of antibody binding sites on the microplate. The washing and decanting procedures remove unbound materials. After the washing step, the enzyme substrate is added. The enzymatic reaction is terminated by addition of the stopping solution. The absorbance is measured on a microtiter plate reader. The intensity of the colour formed is inversely proportional to the concentration of free testosterone in the sample. A set of standards is used to plot a standard curve from which the amount of free testosterone in patient samples and controls can be directly read. The free testosterone kit utilizes a highly specific rabbit anti-testosterone polyclonal antibody at a low binding capacity (Keq x concentration) to keep minimum disturbances of the testosterone-protein equilibrium. The other components in the test system are also optimized in order to not alter the original free testosterone concentration.

Approximately 0.1 mL of serum is required per duplicate determination. Collect 4–5 mL of blood into an appropriately labelled tube and allow it to clot. Centrifuge and carefully remove the serum layer. Store at 4°C for up to 24 hours or at -10°C or lower if the analyses are to be done at a later date. Consider all human specimens as possible biohazardous materials and take appropriate precautions when handling.

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Additional Information

Assay Background

Testosterone is a C-19 steroid secreted from the testis and the adrenal cortex in men and from the adrenal cortex and ovaries in women. Testosterone is also produced by peripheral tissues from androstenedione, which is of little physiological significance in men; in women however, about half of the circulating testosterone is derived from this origin. Testosterone measurements are used mainly for clinical evaluation of hypogonadism in males and hyperandrogenic states in females. Testosterone circulates in the blood bound to three proteins: sex hormone binding globulin (60–80%), albumin and cortisol binding globulin. Only about 1–2% of the total circulating testosterone remains unbound or free. Even though it is still under investigation, most researchers accept the free testosterone determination as a measure of the biologically active fraction. Free testosterone determinations are recommended to overcome the influences caused by variations in transport proteins on the total testosterone concentration.

Typical Standard Curve

Package Inserts


Please note: All documents above are for reference use only and should not be used in place of the documents included with this physical product. If digital copies are needed, please contact us.

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